I often find myself wondering why people in rich countries feel like this is such a compelling argument. I know everyone's financial situations are different, but if the claimed benefits of a thing are taken at face value, why should a price tag of $0 or $100 factor into your decision to take it?
Consider someone with a median software dev salary. Why would the minimal cost of the thing be considered for more than a split second? The effectiveness and safety profile seem to me like they should be all that really matters (probably distantly followed by the social/political/professional pressures).
For Americans, it might be from an assumption that if it's medical, it's life-alteringly expensive, but thats not even the case for these things. But this idea of "why wouldn't you take it, its free!" just doesn't compute for me. There are a lot of free things I have no interest in.
EDIT: Not to mention that it isn't even really free! You're still paying for it with your taxes/insurance premiums.